1. Field of the Invention
The present invention generally relates to a refrigerant cycle system with an improved refrigerant-sealing performance. More particularly, the present invention relates to a receiver-integrated condenser of a refrigerant cycle, and also relates to a receiver separated from a condenser of a refrigerant cycle, which are suitably applied to an automotive air conditioner.
2. Description of Related Art
In a refrigerant cycle of a conventional air conditioner, a receiver and a condenser are integrally formed so that an installation space of the receiver and the condenser in a vehicle is reduced. For example, U.S. Pat. No. 5,546,761 discloses a receiver-integrated refrigerant condenser as shown in FIG. 13. The receiver-integrated refrigerant condenser includes a pair of first and second header tanks 121, 122, and a core portion 123 disposed between the first and second heater tanks 121, 122. Further, separators are disposed in the first and second header tank 121, 122 so that inner spaces of the first and second header tanks 121, 122 are separated into plural spaces, respectively. As shown in FIG. 13, a receiving unit 131 is formed integrally with the second header tank 122 in the receiver-integrated refrigerant condenser. An inner space of the receiving unit 131 communicates with the second header tank 122 through a first communication hole 132 provided at a lower side of the second header tank 122, so that liquid refrigerant condensed in a condensing portion 136 of the core portion 123 flows into the receiving unit 131 through the first communication hole 132. Refrigerant flowing into the receiving unit 131 is separated into gas refrigerant and liquid refrigerant, and the liquid refrigerant is stored in the receiving unit 131. Further, a second communication hole 135 is provided in the second header tank 122 at a lower side of the first communication hole 132. Thus, liquid refrigerant within the receiving unit 131 flows into the second header tank 122 from the second communication hole 135, and flows into a super-cooling portion 137 of the core portion 123.
However, in the conventional receiver-integrated refrigerant condenser, heat from the second header tank 122 is transmitted to refrigerant within the receiving unit 131, and is stored in the refrigerant of the receiving unit 131. That is, when refrigerant amount sealed in the refrigerant cycle is increased after bubbles disappear, liquid refrigerant surface within the receiving unit 131 is increased to become higher. Therefore, liquid refrigerant in the receiving unit 131 is boiled by the transmitted heat, and gas refrigerant is increased in the receiving unit 131. In this case, when a little amount of refrigerant is added in the refrigerant cycle after bubbles disappear, super-cooling degree of the liquid refrigerant is increased, and operation power for driving a compressor of the refrigerant cycle is increased. Further, in a case where the receiving unit 131 is not cooled by cool air, it is difficult to maintain the super-cooling degree in a predetermined range when refrigerant amount sealed in the refrigerant cycle is increased. As a result, refrigerant sealing performance of the refrigerant cycle is deteriorated.
On the other hand, in a conventional receiver separated from a condenser of a refrigerant cycle, all refrigerant from the condenser is introduced into the receiver from an upper side inlet or a lower side inlet of the receiver. When an entire amount of refrigerant flowing from the condenser is introduced from the upper side inlet of the receiver and flows downwardly in the receiver, a gas-liquid boundary surface is readily disturbed within the receiver by dynamical force of refrigerant flowing from the upper side inlet, and gas refrigerant may be mixed to refrigerant flowing into a super-cooling unit. Alternatively, when an entire amount of refrigerant flowing from the condenser is introduced from the lower side inlet of the receiver and flows upwardly in the receiver, because both refrigerant inlet and outlet are provided at the lower side of the receiver, refrigerant from the refrigerant inlet directly flows toward the refrigerant outlet, and it is difficult to cool an upper side of the receiver by refrigerant flowing from the condenser. As a result, when the receiver is used in a high-temperatures condition, liquid refrigerant at an upper side of the receiver may be boiled, and it is difficult to increase the liquid refrigerant surface within the receiver.
In view of the foregoing problems, it is an object of the present invention to provide a receiver with both refrigerant inlets, for a refrigerant cycle system, which improves refrigerant sealing performance.
It is an another object of the present invention to provide a refrigerant cycle system with a receiver, which prevents a disturbance of gas-liquid surface within the receiver, while improving cooling effect of refrigerant at an upper side of the receiver.
It is a further another object of the present invention to provide a receiver-integrated condenser for a refrigerant cycle system, which prevents heat from high-temperature refrigerant of a condensing portion from being directly transmitted to liquid refrigerant within a receiving unit.
According to the present invention, a receiver for a refrigerant cycle system includes a tank member for separating refrigerant from a condenser into gas refrigerant and liquid refrigerant and for storing liquid refrigerant therein, a first refrigerant inlet from which refrigerant from the condenser is directly introduced into an upper side within the tank member, a second refrigerant inlet from which refrigerant from the condenser is directly introduced into a lower side within the tank member, and a refrigerant outlet from which liquid refrigerant within the tank member is introduced to an outside of the tank member. Therefore, refrigerant from the condenser can be flow into both upper and lower sides of the tank member of the receiver from both the first and second refrigerant inlets. Thus, the upper side part of the receiver can be always cooled by refrigerant from the first refrigerant inlet, having passed through the condenser. Accordingly, even when the receiver is used around a vehicle engine or hot air having passed through a radiator flows around the receiver, it can effectively prevent liquid refrigerant at an upper side of the receiver from being boiled. As a result, a liquid refrigerant surface can move upwardly, and refrigerant sealing performance can be improved within the receiver. Further, because refrigerant from the condenser flows into both the upper and lower sides of the receiver from the first and second refrigerant inlets, a part of refrigerant can flow into liquid refrigerant within the receiver from the second refrigerant inlet, and a dynamical pressure of refrigerant from the first refrigerant inlet can be reduced. Accordingly, it can effectively prevent a gas-liquid boundary surface from being disturbed.
Preferably, the receiver further includes an inlet pipe, disposed in the tank member to extend in an up-down direction, through which refrigerant from the condenser flows. Further, the first refrigerant inlet is provided in the inlet pipe at an upper side of the inlet pipe, and the second refrigerant inlet is provided in the inlet pipe at a position lower than the first refrigerant inlet. Therefore, refrigerant from the condenser can readily flow upper and lower sides of the receiver with a simple structure.
More preferably, the inlet pipe is disposed in the tank member in such a manner that refrigerant from the first refrigerant inlet flows toward a top inner surface of the tank member. Therefore, upper side part of the receiver can be further effectively cooled by refrigerant from the first refrigerant inlet, and a disturbance of the gas-liquid boundary surface of the receiver can be effectively prevented.
According to the present invention, the tank member of the receiver can be integrally provided with the condenser, or can be coupled with the condenser through a pipe member. For example, a receiver-integrated condenser includes a core portion having a plurality of tubes through which refrigerant flows in a horizontal direction, a first header tank connected to each one side end of the tubes to extend in a vertical direction perpendicular to the vertical direction, a second header tank connected to each the other side end of the tubes to extend in the vertical direction, a receiving unit for separating gas refrigerant and liquid refrigerant and for receiving liquid refrigerant, and a separator disposed within the second header tank in such a manner that an inner space of the second header tank is partitioned into upper and lower spaces in the vertical direction. In the receiver-integrated condenser, the receiving unit is integrated with the second header tank in such a manner that a communication passage extending over both sides of the separator in the vertical direction is defined by the receiving unit and the second header tank, and the second header tank communicates with the communication passage in such a manner that refrigerant condensed in the core portion flows into the communication passage through the lower space of the second header tank. Thus, it can prevent heat from high-temperature refrigerant in the upper space of the second header tank from being directly transmitted to refrigerant within the receiving unit, and further prevent heat from being stored in the receiving unit. That is, because low-temperature refrigerant continually flows through the communication passage, heat is not stored in refrigerant flowing through the communication passage. As a result, even when cool air is not blown toward the receiving unit, it can restrict liquid refrigerant is evaporated in the receiving unit, and an inner space of the receiving unit can be effectively used for storing liquid refrigerant for the refrigerant cycle.
Preferably, the communication passage communicates with the receiving unit in such a manner that refrigerant in the communication passage flows into the receiving unit from upper and lower sides. Therefore, refrigerant condensed in the core portion flows into the receiving unit from upper and lower sides of the communication passage. Thus, low-temperature refrigerant flowing through the communication passage is inserted between high-temperature refrigerant in the upper space of the second header tank and refrigerant in the receiving unit. As a result, refrigerant sealing performance, for approximately maintaining refrigerant super-cooling degree at a predetermined degree relative to an increased refrigerant amount in the refrigerant cycle, can be improved. Accordingly, it can prevent operation power for operating the compressor from being increased due to super-sealing refrigerant amount in the refrigerant cycle.
More preferably, refrigerant in the communication passage flows into the receiving unit through a first communication hole at a lower side and a second hole at an upper side of the first communication hole. Further, a ratio of a second opening area of the second communication hole to a first opening area of the first communication hole is in a range of 2-4. Thus, refrigerant sealing performance of the refrigerant cycle can be further improved.